Grinding gauge or holder for thread-cutting tools



Nov. 7, 1944. A. RINGZELLI 2,362,306

GRINDING GAUGE 0R HOLDER FOR THREAD CUTTING TOOLS Filed Sept. 24, 1942 Patented Nov. 7, 1 944 oiti pINGflGAU E on HOLDER. FOR" l p 'IfH RE AD- CUTTING rooLs. j

H g 1 "Arthur Itingcelli, lhicago, Ill. Applicationlsepteniber 24, 19.42, Serial No. 459,528.

" Y 1 QS QIain iSQ (01.51 221),

making art, and for convenience, the present'de;

, vice is shown as adapted for-"holding a tool for making United States standard V-threads.

'The Objects of this invention are. to provide an improved gauge or holder for grinding tools which will be exceedingly simple in. construction and durable and efficient in use; to provide a holder whereby such tools may be. accurately ground by an inexperienced person; to p-rovide 'a tool holder for grindingthreading tools which will serve as a master grinding gauge whereby the tools may be'accurate'ly ground in the-first instance, and may belshar-pene'dto the required degree of accuracy; to provide means whereby block to provide faces or supporting surfaces 15 or rake, all of which isWell known in thetool 22:;

an' inexperienced person may grind thread vcutting tools in the correct manner equalingxior surpassing the-accuracy of the finest skilled-me chanic; to provide-a jig or holder. ,fo'r grind ing external thread cutting tools, and-also internal thread cutting-tools; and to provide such other advantages and improvements as will bedescribed more fully in the following descrip'-'. tion.- In the accompanying drawing illustrating: this invention, N f Fig. 1 is a perspective view showingtthe'use' of the holder for grindinga'tool' on a surface grinder; v v, Fig. 2 is a cross sectional view or the gauge showing the same in position in the grinder; I. i

1 Fig. 3 is a plan View of the gauge or holder taken substantially on the line 3'-3 of Fig. 2 t Fig. 4 is a sectional view takensubstantia'lly on the line 44 of Fig. 2;

Fig. 5 is a perspective particularly showingjthe" face of the gauge having the grooves and'clamping means for holding an internal thread cutting tool; and a ,Fig. 6 is a perspectiveview showing the posif tioning of the internal thread'cutting to'ol irithe and 6- whichin the present I instance are arrangedatran angle 03603 to each other as shown. The sides l3 and J4 have slots l! and H! which.

are substantially parallel to each other but which are at any desired. angle to the sides to provide. correct grinding anglesfor the opposing surfaces of, the tool. It willlalso be noted that the botf, toms ofv theslots are parallel to the sides .of. the.

gauge. Set screws 19 and '20 are provided for clamping or holding'thetool in the respective slots.* The gauge is'also iprovided'with a clamp.

21 and setscrew orcIam'ping screw 22 withfa knurled head for holding the tool in the various slots, threaded holes 23' and 24 beingprovided for receiving the screw to hold the clamp fastening positions adjacent to the;slotsl1 and When a tool for g rinding-eirternal" threads,

such as1the. tool 25 is to be sharpened, it may first be placed in the slot I8 as'shown and the set 'screw 29' tightened 'to hold it firmly against the side of the'slot. It is then clampedsecurely. in position by the ;;clamp "18 preparatory 'for grinding. The'gauge or =jig may then be placed onthe b'ed ortable 9 and will be held automatically'bythe magnetic action. The gauge is positioned so that it will move longitudinally with. the movement of the table with the beveled face IS in contactwith the'bed. -This wil1 hold the tool"25 substantially in the-position shown in, Figs. -1"andi'2.withone of the surfaces or sideszfi'bf the cutting point to be engagedby the 1 tool is then clam-ped in a similar manner. in the .slot' l1 and the gauge is then turned over so-that the'beveled side'lfiwill rest on the table andithe other side or surface '2 0 the grinding point may:

be ground as described which will give the desired "angle of between the surfaces 26 and 2! and thepoint will also have'the necessary or desired rake as shown;

'Ifhe gauge orji g is also'adaptedfor accurately grinding the tools for cutting-internal thread such as the" tool shown" at" 28 which have their fcuttihgportions 29' at substantially right angles" to the shankf These tools may be made from either rounder square stock with theirnutting points formed inany well known'manner. The: gauge or block l0*'i's pr'ovided on the'side I 'I with con-2 vergingjgrooves 30 and 3| for receiving the shank of'thetool 28. These grooves are positioned at screw-33.vvhich coacts-with the clamp 2l for holding'ithe tool'secur ely' in'position." When thejig. or fixture is usedfor grinding such'tools, it ispositioned on the bedas shown in Fig. 6 and a screw with a small head is used so that there is no danger of its coming in contact with the grinding wheel. The use of the device for grinding such tools or bits for internal threads Will be readily understood by those familiar with such 1 shop practice.

The gauge or jig is preferably made of hardened tool steel and accurately ground or finished in order to provide for the accurate grinding of the tools, and also to give the samelong life,

There are no small or delicate parts to get'out of order and no adjustments to be madeso' that accurate grinding may be doneby inexperienced persons. 1

While I have described the gauge or jig as being applied to a magnetic chuck, it will be apparent that itmay also be used by moving the same manually on the bed, provision being made to bring the point into contact with the grinding wheel, or if desired, any suitable guideways (not shown) may be utilized for supporting and guiding the movement of the gauge.

It will also be noted that changes may bemade in the shape of the parts or construction of the same-in order to hold different forms of tools, and therefore I do not wish to be limited to the particular construction shown and described exceptas set forth in the following claims in which I claim:

1. A new article of manufacture comprising a gauge for grinding thread cutting tools, consisting of an elongated block of substantially rectangular cross section with the exception that two opposite sides have portions which converge at approximately 30 to the center plane of the block, each of the latter sides having a substantially transverse slottherein for receiving the tool to be ground, said slots being parallel to each other and at an angle to the length of the block corresponding to the desired rake of the cutting end of the tool to be sharpened, and means for holding the tool in said slots.

2. A gauge or jig for sharpening thread outtin-g tools; comprising an elongated block having portions of the sides converging for engagement with the table of a surface grinder and having slots l1 and IS in the respective sides having the converging portions and positioned at an angle to the sides, the bottoms of the slots being substantially parallel to the sides whereby a tool held in either slot will be presented to the grinding wheel at the right angle for grinding the cutting edge when the converging portion of the other side of the block is resting on the table, set screws in the block for engagement with tools when placed in the slots and clamping means for clamping the tools in the slots.

'3. A holder for the purposes set forth consisting of a block of substantially rectangular cross section, but having portions of the top and bottom converging toward one of the sides to provide oppositely disposed faces for engagement with the bed of a grinding machine, slots in the top and bottom which are parallel with each ported in the slot on the opposite side, the end of the tool will be supported in position to grind the opposite'face of the cutting portion of the tool,

4. A compound gauge or jig for supporting both external and internal thread cutting tools, having slots in the opposite sides for receiving a .toolfor. cutting external threads, means for holding the tool in the slots, portions of the said opposite sides of the block being beveled to engage withthe table of a surface grinder, the arrangement being such that a tool placed first in one ofthe slots and ground and then in the opposite slot and ground, will be held securely in position for accurately grinding the opposite faces of the cutting point of the tool, said block also having converging grooves on one face II which is not beveled, for supporting a tool for cutting internal threads having a shank with ,a cutting portion at substantially right angles thereto, and means for clamping the last named tool in said grooves, the arrangement being such .that the sides of the cutting point of the tool will be presented at the proper angle to be ground when the gauge and tool are mounted in operative position on a surface grinder.

5. A- holder for holding tool bits to be ground, comprising a body having means on opposite sides thereof for supporting the tool -bits, and having converging surfaces on said opposite Sides adapted to support the holder in alternate positions on the bed of a surface grinder'to present a tool bit for grinding whereby opposite sides of thebit Will be ground .at the desired angle corresponding to the relative positionsof the converging surfaces.

6. A grinding jig for grinding thread cutters, comprising a body having grooves and clamping means onthe top and bottom faces thereof for holding a thread cutter in'predetermined positions with respect to the body, said body having converging surfaces: on the top and bottom faces serving to support the body in positions on the bed of a surface grinder for presenting the cutting end of a tool to the grinder for grinding inclined surfaces thereon, substantially as described. i

7. A new article of manufacture comprising a tool grinding jig having a body with converging sides adapted to hold the body on the bed of a surface grinder at predetermined angles with respect to the grinder, said body havingmeans coacting with the top and bottom faces for holding a tool for cutting external threads, and'having means on the side opposite the converging faces for holding a tool for cutting internal" threads, the arrangement being suchthat when a tool is held in the jig on the bed of a surface grinder, its cutting end will be held in proper position for accurate grinding.

8. A gauge for use in grinding thread cutting tools on a surface grinder, comprising a block of substantially rectangular cross section with the exception that two opposite sides have portions which converge at a predetermined angle to the center plane of the block, each of said opposite sides having a substantially transverse slottherein for receiving the tool to be ground, said slots being parallel to each other, and at'an angle to the length of the block corresponding to the desired rake of the cutting end of the tool to be sharpened, and means for holding the tool in the respective slots.

AR'IHUR-RINGZELIJ. 

